1. Field of the Invention
The present invention relates to a distributed resources sharing method using weighted sub-domains in a generalized multi-protocol label switching (GMPLS) optical network, and more particularly, to a distributed resources sharing method of distributing shared resources by using information on weighted sub-domains in order to prevent waste of idle resources caused from concentration of allocated resources at the time of sharing resources of backup paths.
This work was supported by the IT R&D program of MIC/ITA [2005-S-101-02, Multimedia QoS Routing Technology Development].
2. Description of the Related Art
In a generalized multi-protocol label switching (GMPLS) optical network configured with optical cross connectors (OXCs), recovery time is longer than that of a synchronous optical network/synchronous digital hierarchy (SONET/SDH) network, so loss of traffic is very large. Therefore, there is needed a mechanism for survivability of the optical network. In addition, the mechanism needs to be operated so as to effectively use resources of the optical network.
Fiber obstacles in the optical network denote obstacles to all optical paths passing through a fiber. Each optical connection has a data rate of 10 Gbps. The optical connection in the GPLS optical network is implemented with a coarser granularity of 10 Gbps than an existing packet network (for example, a multi-protocol label switching (MPLS) network), so that loss of resources caused from the obstacle is increased. Therefore, utilization of connected resources in the optical network is more important than the existing network, and the mechanism for effectively using the resources of network is required. In an existing protection mechanism, other backup paths are selected by using only the shared risk link groups of the working paths, so that the recovery from the obstacle can be rapidly performed.
However, in the mechanism, the resources cannot be effectively used due to an insufficient method of sharing resources between the backup paths. In order to compensate for the shortcomings, a mechanism for sharing the resources between the backup paths has been proposed.
Although the efficiency of the resources can be improved by the mechanism, unbalanced sharing of the resources between the backup paths has not been considered. In other words, since the backup paths may be concentrated on one site, idle resources may not be used. Since the idle resources cannot be effectively used, the efficiency of the total resources is decreased.
As an example, there has been proposed a mechanism for minimizing network resource usage in terms of efficiency of the resources. The mechanism is based on an assumption that O-E-O (optical-electronic-optical) conversion in a mesh-type optical network is applied to some nodes but not all the nodes according to the status of system at the time of setting up optical connections (that is, light paths). Resources contention is caused from selection of the same resources t the time of setting up working paths or working/backup paths. In the existing mechanism, the network resources are minimized by considering signal quality, wavelength continuity, and path diversity for allocation of resources. However, similarly to the resource control mechanism where the O-E-O conversion is applied to all the nodes, the mechanism leads to concentration of the resources, so that the resources cannot be effectively controlled.
In an alternative example, there has been proposed a mechanism where available resources are firstly searched from a pool of resources at the time of setting up backup paths, and the resources are used for recovery. However, in the mechanism, a connection control method is not considered, so that the resource sharing is difficult in case of occurrence of concentration of backup paths.